The object of this study was to determine whether coronary collateral resistances were dependent on the direction of perfusion and to investigate whether a pattern of collateral growth with gradual circumflex occlusion could be discerned. In 12 dogs an Ameroid occluder was placed on the circumflex for 1 month, and six dogs for 3 months; 12 dogs served as controls. The circumflex, left anterior ...

Collateral vessels are anastomoses that connect adjacent arterial trees and reroute perfusion around obstructed arteries or veins. Variation among individuals in the extent of native collaterals (ie, number or diameter) may serve as a prognostic determinant of stroke severity and improve clinical risk benefit decisions for treatment options. Angiographic studies grading collateral circulation i...